Vehicle emission has become a leading source of atmosphere pollution with increasing vehicle population. Environmental issues of air pollution, acid rain, green house effects, etc., due to fuel vehicle emission have shadowed the development of vehicles, and people also are more devoted to the research and development of clean-fuel electric vehicles with environmental protection while improving fuel vehicles in view of rapid consumption of oil energy sources. Both a hybrid powered vehicles and a pure electric vehicle have earned increasing attention of people, but a power source of the electric vehicle, i.e., a power battery pack, contributes to a highest part of the production cost of the vehicle and also an crucial factor limiting the endurance mileage of the electric vehicle. Therefore, the pure electric vehicle which greatly depends upon the development of the battery has not gained any crucial breakthrough during the development in the past dozens of years, and the hybrid powered vehicle has the advantages of both internal-combustion engine and pure electric vehicles to be advantageous in terms of low oil consumption, low emission, a long driving distance, etc., and thus is the focus of attention of various vehicle manufactures worldwide and also a relatively feasible solution.
The hybrid powered vehicle is provided thereon with two power sources, i.e., an engine and a battery, and the management of the two power sources is important in terms of ensuring normal and efficient operation of a system and durability of the system. An accumulator with good performance as a worldwide puzzle has been in slow development relative to the rapid development of modern electronics and information technologies, so the management of the battery becomes particularly crucial at present.
In a commonly used method for limiting charging and discharging current of a battery, State Of Charge (SOC), voltage and temperature signals of the battery are collected in real time, and then a limiting torque is derived from a lookup table based upon experimental data. An implementation of this method depends upon a large amount of experimental data and these experimental data have to be modified in a timely way as the aging of battery or the varying environment, which may be time and effort consuming.